JP2008161766A - Cleaning apparatus and cleaning method of contaminated soil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning apparatus of contaminated soil capable of stably cleaning soil contaminated by heavy metal, or the like with the simple apparatus. <P>SOLUTION: In the cleaning apparatus for cleaning contaminated soil by transferring it with gravity for each process, the contaminated soil is agitated and cleaned by a drum type cleaner 4, and is classified by a wet type vibration sieve 5. A coarse content stored in a sieve 5a is stored in a first tank 6, and a fine granule content passed through the sieve is stored in a second tank 7. The first and second tanks are disposed under the ground surface, and a hopper 3 for feeding the contaminated soil to the drum type cleaner is installed at a low position enabling the direct charge of the soil by a hydraulic shovel 2 or the like. With this constitution, the soil is charged into the hopper without using a conveyor, or the like. Furthermore, an operator for the hydraulic shovel mounts a reflecting mirror 8 visible inside the hopper, and appropriately charges the soil into the hopper, while supplying cleaning water into the hopper and blowing compressed air, thereby preventing the adhesion or coagulation of the soil inside the hopper. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cleaning apparatus and a cleaning method for cleaning soil contaminated with harmful substances such as oil and heavy metals.

In recent years, it has been frequently reported that soil is contaminated with leaked oil, organic solvents, heavy metals, etc. in urban areas, factory sites, shooting ranges, and the like around gas stations. If the soil is contaminated with harmful substances in this way, it may be mixed into groundwater, flowing into rivers, or hindering land reuse.
For the treatment of such contaminated soil, a method in which it is buried as industrial waste in a disposal site or disposed of, or a method in which the pollutant is removed by incineration or washing to repair and reuse the soil is generally adopted. . However, the method of burying and discarding in the ground makes it difficult to secure a disposal site due to problems such as environmental conservation, and the method of incineration has a problem of high processing costs. For this reason, in recent years, there are many examples of adopting a cleaning method that is excellent in terms of environmental conservation and can be processed at low cost.

As disclosed in Patent Document 1 or Patent Document 2, a general purification method by cleaning contaminated soil is to transport the contaminated soil by a conveyor, etc., and to add it to a drum-type cleaning machine, etc. . And many methods are used to separate the contaminants that have been kneaded together with water, cleaning agents, etc. from the surface of the soil particles and transferred to the aqueous phase, followed by classification and separation of the contaminated parts. Yes.
JP 2005-28290 A JP 2004-261700 A

In such a contaminated soil cleaning device, machines and equipment used in each soil cleaning process are arranged in series from a high position to a low position in order of the process so that the transport and cleaning process of the contaminated soil can proceed efficiently. Has been. Therefore, the equipment used in the first process, the soil disruption process, that is, the hopper and the soil washing machine for introducing contaminated soil are placed at the highest place in the washing equipment, and the equipment used in the subsequent process is These are installed sequentially below the hopper and soil washing machine. As described above, since the hopper and the soil washing machine are installed at a high position, the soil to be purified must first be transported to a high position, and a transport machine such as a conveyor is required.
In addition, if the conveying path until the contaminated soil is slurried and washed as described above is long, soil containing a large amount of silt or clay is likely to adhere to the hopper or conveyor and cause the clogging of the washing path. May prevent proper cleaning.

  This invention is made | formed in view of the above situations, The objective is to provide the washing | cleaning apparatus and washing | cleaning method of contaminated soil which can perform the injection | pouring and conveyance of contaminated soil efficiently. is there.

  In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a hopper into which soil contaminated with a harmful substance is introduced, and the soil is introduced from an opening provided at a lower portion of the hopper, and is added to the soil. A drum-type washer for cleaning, a vibrating sieve for classifying the soil discharged from the drum-type washing machine, and a plurality of tanks for collecting the soil classified by the vibrating sieve, the hopper comprising: It is provided at a position where the soil can be input by a construction machine for earthwork capable of scooping and transporting the ground surface and soil, and the vibrating sieve is discharged from the drum type washing machine and transferred by gravity The washed soil is arranged at a position where the soil can be screened, and the plurality of tanks contain the soil that has passed through the vibrating screen and the soil that has remained on the vibrating screen by gravity. It is arranged at the position, at least one of the plurality of tanks, to provide cleaning apparatus of contaminated soil, wherein a part or the whole is installed at a position to be the subsurface.

In this contaminated soil cleaning device, it is possible to directly input the contaminated soil into the hopper with a construction machine for earthwork, for example, a hydraulic shovel that travels on the ground surface and scoops and transports the soil. The conveying means is simplified. As a result, the efficiency of input of contaminated soil is improved, and the cost can be reduced.
In addition, since the hopper, drum type washer, vibrating screen and tank used in the cleaning device are arranged in the order of the cleaning process from high to low, the contaminated soil is moved by its gravity and used in the next process. Can be sent to other devices. As a result, the soil can be transferred efficiently in the cleaning process, and the cost for maintenance and management of the cleaning device is reduced. Furthermore, by arranging the tank so that part or all of the tank is below the ground surface, the position of the hopper where the soil is initially charged can be set low, and the soil can be input efficiently. Become.
On the other hand, since contaminated soil can be put directly into the hopper using a hydraulic shovel or the like, the soil transport route until slurrying is shortened, and even if the soil contains a lot of silt or clay, It can reduce that it adheres and smooth conveyance is inhibited. In addition, it becomes easy to manage the operation state so as to prevent soil adhesion and the like.
In the present invention, the vibration sieve may be a single one or may include a plurality of vibration sieves having different mesh sizes. By using a plurality of vibration sieves, the soil separated from the slurry can be classified into a plurality of ranges according to the particle size and taken out.

  The invention according to claim 2 is the cleaning apparatus for contaminated soil according to claim 1, comprising one or more reflecting mirrors that allow the operator of the construction machine for earthwork to visually recognize the hopper. To do.

  In this contaminated soil cleaning apparatus, the operator of the construction machine for earthwork can visually recognize the inside of the hopper through the reflecting mirror, and can recognize the residual state of the soil in the hopper. Therefore, the operator can appropriately input the contaminated soil without excess or deficiency by adjusting the input amount or the input speed. As a result, it is possible to prevent the soil that has been excessively charged into the hopper from solidifying or the shortage of the soil that is charged into the drum type washing machine, and to perform the cleaning process efficiently.

  The invention according to claim 3 is the cleaning apparatus for contaminated soil according to claim 2, wherein the reflecting mirror is supported so that at least one of the position of the mirror surface, the vertical angle and the horizontal angle can be changed. It shall be.

Even if the operator moves due to the traveling of the construction machine for earthwork, the position of the reflecting mirror provided in the contaminated soil cleaning device, the vertical angle, and the direction angle when turning in the horizontal direction are changed. The operator can see the hopper's soil inlet and the inside, and can accurately grasp the input status of the contaminated soil.
The reflecting mirror may be adjusted so that the operator can visually recognize not only the inside of the hopper but also the water supply equipment provided near the hopper and the state on the vibrating screen.

  The invention according to claim 4 is the cleaning apparatus for contaminated soil according to claim 3, wherein the operator of the earthwork construction machine operates from the cockpit of the earthwork construction machine, the position of the reflecting mirror, 4. The apparatus for cleaning contaminated soil according to claim 3, further comprising a reflector operating device that adjusts at least one of a direction angle and a horizontal direction angle.

  In this cleaning apparatus, the operator of the construction machine for earthwork can adjust the reflecting mirror to an appropriate position and angle while looking at the reflecting mirror, and the reflecting mirror can be adjusted efficiently and appropriately.

  The invention according to claim 5 is the cleaning apparatus for contaminated soil according to claim 3, wherein the reflector is configured so that the operator can visually recognize the inside of the hopper based on the position information of the operator of the construction machine for earthwork. And a reflecting mirror adjusting device that adjusts at least one of the position, the vertical angle, and the horizontal angle.

  In this cleaning device, when the operator moves due to the traveling of the construction machine for earthwork, the position and angle of the mirror are quickly adjusted according to the moved position, and the operator can always visually check the state in the hopper. can do.

  The invention according to claim 6 is the cleaning apparatus for contaminated soil according to any one of claims 1 to 5, wherein either one of supply of cleaning water and blowing of compressed air in the hopper or It shall be equipped with the soil adhesion suppression means which performs both.

The soil adhesion suppression means includes those that function to fall to the drum type washing machine before the soil adheres to the hopper, and those that function to send the adhered soil to the drum type washing machine. It is desirable to have both functions.
In this contaminated soil cleaning apparatus, it is possible to prevent soil adhesion by supplying cleaning water to the vicinity of the inlet of the contaminated soil of the hopper or to the inner wall surface. Further, compressed air is supplied together with the supply of the cleaning water or instead of the supply of the cleaning water, and the wind pressure can prevent the contaminated soil from sticking to the inlet or the inner wall surface of the hopper.
The washing water supplied into the hopper is used as washing water for washing the inner surface of the hopper, and then introduced into the drum type washing machine together with the soil. It is used as washing water.

  The invention according to claim 7 is the cleaning apparatus for contaminated soil according to claim 6, wherein the supply of the cleaning water causes the cleaning water to flow down to the inner surface of the hopper.

  In the state where cleaning water is supplied to the inner surface of the hopper and a flow of cleaning water is formed along the inner surface, even if the soil contains a lot of silt or clay, it is difficult to adhere to the inner surface of the hopper. It can be made to flow down by running water. Therefore, it is suppressed that soil adheres and stays in the hopper.

  The invention according to claim 8 is the cleaning apparatus for contaminated soil according to claim 6, wherein the supply of the cleaning water jets high-pressure cleaning water toward the inner surface of the hopper.

  The supplied washing water is sprayed at a high pressure, so that the soil adhering to the inside of the hopper can be peeled or crushed to flow down, and the soil adhering to and staying in the hopper can be effectively removed. .

  The invention according to claim 9 is the cleaning apparatus for contaminated soil according to claim 6, wherein the supply of the cleaning water discharges the cleaning water from a discharge port provided on the wall surface of the hopper, and the inner surface of the hopper The blowing of the compressed air stops discharging the washing water from the discharge port, and blows out the compressed air from the discharge port or from an air outlet provided in the vicinity of the discharge port. To do.

  In this cleaning device, the supply of cleaning water effectively suppresses the soil from adhering to the hopper, and when the soil adheres, particularly when the discharge port of the cleaning water is covered and blocked by the soil. Compressed air can be blown out from the discharge port, and the attached soil can be pushed up by wind pressure, peeled off and dropped.

  The invention which concerns on Claim 10 WHEREIN: In the washing | cleaning apparatus of the contaminated soil in any one of Claim 6-8, The supply amount of the said washing water, the injection angle of the high pressure washing water injected, or the injection speed is set. It shall be adjustable according to the state of the soil thrown into the hopper.

  The invention which concerns on Claim 11 is a washing apparatus of the contaminated soil in any one of Claim 6-8. The up-down direction angle which sprays the said compressed air, the angle of a horizontal direction, the amount of air to spray, or compressed air It is assumed that the pressure can be adjusted according to the state of the soil put into the hopper.

  In this contaminated soil cleaning device, the amount of cleaning water supplied into the hopper, the angle of spraying at high pressure, the spraying speed or the spraying amount should be adjusted according to the proportion of silt / clay contained in the soil and the water content. Can do. Thereby, adhesion of soil can be suppressed, and even if adhesion occurs, it can be appropriately peeled off and put into a drum type washing machine. Moreover, the spray angle of compressed air, the angle to spray, a pressure, etc. can also be adjusted, the soil adhering to any position in a hopper can also peel, and the inside of a hopper can be maintained in a favorable state.

  The invention according to claim 12 is provided with a hopper at a position where the soil can be input by a construction machine for earthwork capable of scooping and transporting soil contaminated with traveling and harmful substances on the ground surface, While the operator of the construction machine observes the state of the soil in the hopper through a reflector, the soil is introduced directly into the hopper by the construction machine for earthwork, and the drum-type washing machine is pulled from the hopper by gravity. In addition to introducing soil into the soil, washing water is added to wash the soil, and the soil discharged from the drum washer is transported onto the vibrating screen by gravity, sieved by the vibrating sieve, and sieved by the vibrating sieve. Each of the soils is transported by gravity, and at least one of the plurality of soils is transferred to a tank installed in a position where part or all of the soil is below the ground surface. The present invention provides a method for cleaning contaminated soil, characterized in that each soil is stored, the soil stored in each tank is taken out, and transported to perform the next step.

  In this cleaning method, the contaminated soil can be efficiently and appropriately put into the hopper, and the cleaning process, the classification process, and the process of storing the classified soil in the tank can be performed by movement by gravity. This enables efficient processing.

  The invention according to claim 13 is the method for cleaning contaminated soil according to claim 12, wherein either one or both of supplying cleaning water and spraying compressed air is performed in the hopper, and the hopper for the soil is used. It is assumed that the soil is introduced by the construction machine for earthwork while suppressing adhesion to the inside.

  The invention according to claim 14 is the method for cleaning contaminated soil according to claim 13, wherein when the soil is put into the hopper, the cleaning water is allowed to flow down to the wall surface in the hopper, When soil adheres to the surface, the washing water is sprayed under high pressure or compressed air is sprayed.

  In the above washing method, even if the amount of silt / clay contained in the soil and the water content is large, the soil is effectively suppressed from adhering in the hopper, and when the adhesion occurs, the soil is efficiently peeled off, It can be put into a drum type washer.

  The invention according to claim 15 is the cleaning method for contaminated soil according to claim 14, wherein the adhesion of soil occurs in the hopper, the discharge port provided in the wall surface of the hopper is covered, and the wall surface in the hopper When the supply of the wash water flowing down is hindered, after the supply of the wash water flowing down the wall surface is stopped, the compressed air is blown from the same discharge port to remove the soil on the discharge port, and again in the hopper A step of returning to a state in which a predetermined amount of washing water can flow down from the discharge port to the wall surface.

  In this cleaning method, it is possible to efficiently suppress soil adhesion and peel off the adhered soil with simple equipment.

  The invention according to claim 16 is the cleaning method for contaminated soil according to any one of claims 12 to 15, wherein the step of throwing soil into the hopper by the construction machine for earthwork is the construction for earthwork A machine operator performs an operation of adjusting at least one of the position of the reflecting mirror, the vertical angle and the horizontal angle, visually confirms the inside of the hopper, and confirms the state in the hopper. And

  In this cleaning method, the operator of the construction machine for earthwork can efficiently and appropriately put the contaminated soil into the hopper while checking the state in the hopper.

  As described above, in the contaminated soil cleaning apparatus and cleaning method according to the present invention, the contaminated soil can be directly input into the cleaning apparatus by the construction machine for earthwork, and in the cleaning process after the input, It can be transported by dropping or sliding down due to gravity, enabling efficient processing. Further, even contaminated soil with a high silt or clay content is prevented from adhering to the apparatus, and stable and smooth treatment can be performed, thus facilitating operation cost management. Furthermore, since the equipment scale can be made smaller than before, it is also beneficial for environmental protection.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a contaminated soil cleaning apparatus according to an embodiment of the present invention.
The contaminated soil cleaning apparatus 1 is disposed in connection with a hopper 3 into which contaminated soil is introduced from a hydraulic shovel 2 or the like, which is a construction machine for earthwork, and a lower opening 3 a of the hopper 3. A drum-type washing machine 4 for washing the soil, a wet vibrating sieve 5 for separating the washed soil (slurry) in which contaminated soil and water are mixed into coarse and fine particles, and the wet vibrating sieve 5 A first tank 6 that collects the coarse particles remaining on the top, a second tank 7 that collects slurry containing fine particles that have passed through the mesh of the wet vibrating screen 5, and the vicinity of the soil inlet of the hopper 3 And a reflecting mirror 8 for visually recognizing the inside.

The hopper 3 is disposed at a height and position where the contaminated soil can be directly input to the soil input port of the hopper 3 by the hydraulic shovel 2. In the present embodiment, the soil inlet is at a height of about 5 m from the ground surface.
The drum type washing machine 4 is arranged so that the soil falling from the lower opening 3a of the hopper 3 is introduced into the cylindrical washing machine, and the amount is adjusted from the contaminated soil put into the hopper 3 It is intended to be introduced into the washing machine. Then, washing water is added to the contained contaminated soil and stirred and mixed. By agitation and mixing, the soil mass is crushed and slurried, and further agitation moves the contaminants from the contaminated soil to the aqueous phase.
The drum type washing machine 4 is arranged so that the inside of the washing machine is inclined so that the slurry-like soil to be stirred and mixed moves by gravity and moves toward the soil discharge port 4a.

The wet vibration sieve 5 is provided at a position where the soil discharged from the drum-type washing machine 4 is transferred by gravity, and the transferred soil is dropped onto the sieve 5a. And it shakes, adding water as needed, and isolate | separates the slurry containing a fine granule under a sieve. The slurry that has passed through the sieve 5 a flows down along the inclined surface 5 b and is dropped into the second tank 7. Coarse particles that do not pass through the mesh of the sieve 5a are conveyed downward by vibration on the inclined and supported sieve, discharged from the sieve 5a, and stored in the first tank 6.
In the present embodiment, the sieve 5a having a mesh of 2 mm is used, but the size of the mesh can be appropriately selected according to the type of contaminants, the quality of soil, and the like.

  The first tank 6 accommodates the coarse particles remaining on the sieve 5a as described above, and most of the contaminants adhered to the coarse particles by the drum type washer are peeled off. , Pollution concentration is low. On the other hand, the second tank 7 contains slurry having a high concentration of contaminants that have passed through the mesh of the sieve 5a. Both the first tank 6 and the second tank 7 are buried underground, and the soil classified by the wet vibrating sieve 5 is put into the first tank 6 and the second tank 7 by gravity, respectively. It is arrange | positioned under the wet vibration sieve 5 so that can be performed.

  As described above, the hopper 3, the drum-type washing machine 4, the wet vibrating screen 5, the first tank 6 and the second tank 7 used in the washing apparatus 1 sequentially remove the soil put into the hopper 3 by gravity. It is arranged in order of process from the top to the bottom so that it can be transferred to the next process. By embedding the first tank 6 and the second tank 7 in the basement, the position of the hopper can be set low even if soil is transferred from above to below using gravity, such as a hydraulic shovel. It is easy to put soil directly into the hopper with a self-propelled construction machine.

  As shown in FIG. 1, two reflecting mirrors 8 are attached to the upper part of the hopper 3 near the soil inlet, and these reflecting mirrors 8 are located near the soil inlet of the hopper 3 and inside the hopper 3. And the lower opening portion of the hopper is provided so that the operator of the hydraulic shovel 2 can see. The reflecting mirror 8 may be supported by a support column raised from the ground surface, or may be supported by a gantry that supports the hopper 3 and the drum type washing machine 4. Further, it may be supported by the hopper 3 or the drum type washing machine 4.

  The reflecting mirror 8 is preferably provided so that the position of the mirror surface, the vertical angle and the horizontal angle can be adjusted. Construction machines such as a hydraulic shovel travel and move on the ground surface, and it is possible to make the inside of the hopper visible from any position moved by adjusting the angle and position of the mirror surface. The position and angle may be adjusted manually by the operator, but shall be provided with a drive device, and the direction and angle of the mirror surface by means of a device (not shown) placed at the operator's hand of the hydraulic shovel 2 It is desirable that these changes can be appropriately operated. The operation signal from the operator may be transmitted by wire, but it is preferable that the operation signal can be operated wirelessly using radio waves, light, or the like. Further, remote control by a supervisor other than the operator may be possible. On the other hand, a sensor for detecting the position of the operator of the hydraulic shovel 2 is provided, and the angle and position of the mirror surface of the reflecting mirror 8 are adjusted based on the position information obtained by this sensor, thereby The operator of the shovel 2 can always see the state in the hopper well without operating the reflecting mirror 8 himself.

As shown in FIG. 2, a plurality of nozzles 9 for injecting cleaning water at a high pressure are provided at the periphery of the soil inlet of the hopper 3. This nozzle 9 is set so as to inject high-pressure water toward the inner wall surface where the soil in the hopper slides down, and as shown in FIG. 3, the nozzle 9 is rotated so as to swivel within a predetermined angle θ. It is possible. Thereby, the soil lump adhering to the inner wall surface of the hopper 3 can be softened and dropped into the drum type washing machine 4. Moreover, by rotating the injection direction of high-pressure water, high-pressure water can be sprayed over a wide range in the hopper, and the adhesion of soil in the hopper can be efficiently suppressed.
Moreover, the nozzle 9 which injects washing water at high pressure can also be attached to the water supply pipe 10 penetrating the inner wall surface of the hopper 3 as shown in FIG.

The washing water supplied into the hopper may be supplied so as to flow down the wall surface of the hopper 3 by gravity instead of the one injected at a high pressure or together with the one injected at a high pressure. In this way, the washing water that flows down the wall surface can be supplied from above the hopper or through the wall surface, similarly to the washing water jetted at a high pressure.
FIG. 5 is a plan view (a) and a side view (b) showing an example of a hopper to which cleaning water is supplied so as to flow down the wall surface.
The hopper 30 has a large number of openings 31 formed on the wall surface, and water supply pipes 32 arranged on the outside of the hopper 30 are connected to the respective openings 31, and the openings 31 serve as discharge ports for washing water. . The washing water supplied from these discharge ports continuously flows down the wall surface of the hopper. In this way, the presence of running water on the wall surface suppresses the soil from adhering to the wall surface, and the soil block is suppressed from staying in the hopper while adhering to the wall surface.

  On the other hand, instead of supplying cleaning water into the hopper, or together with supplying cleaning water, compressed air can be blown toward the hopper. This compressed air is provided with a compressed air outlet near the upper edge or through the wall surface of the hopper 3 and sprays the compressed air against the soil in the hopper in the same manner as the nozzle 9 for injecting washing water at a high pressure. To do. The wind pressure to which the compressed air is blown can prevent the soil from adhering, or can promote the peeling of the adhering soil and dropping it onto the drum type washing machine 4.

  Further, for example, as shown in FIG. 5, it is conceivable to use a discharge port provided on the wall surface of the hopper for blowing out the compressed air. When soil has adhered to the wall surface, the discharge of the washing water from the discharge port is temporarily stopped, and the compressed water is blown out from the discharge port by switching so that the compressed air is supplied to the water supply pipe. Thereby, the soil adhering to the wall surface of the hopper is pushed up by the pressure when the compressed air is blown out, peeled off from the wall surface of the hopper, and falls into the drum type washing machine. Further, instead of blowing out from the discharge port of the washing water, a compressed air blowout port may be provided along with the discharge port, and the blowout port may blow out.

  It should be noted that the amount of cleaning water supplied to the hopper 3 from the discharge port, the injection angle of the cleaning water injected from the nozzle, the injection speed, the injection amount, etc. can be adjusted and included in the state of the soil, for example, the soil Corresponding to the ratio of the silt / clay and the water content, the amount of washing water can be increased, or the injection speed or the injection amount can be adjusted to be large when the soil easily adheres to the hopper. The compressed air blown into the hopper 3 can also adjust the blowing angle, the amount of air to be blown, or the pressure of the compressed air according to the state of the soil, etc., and the compressed air blown out from the discharge port in place of the washing water is also pressure Can be adjusted. Furthermore, the number of discharge ports for cleaning water, nozzles for injecting high-pressure cleaning water, and injection ports for compressed air can be increased or decreased as necessary. Accordingly, the discharge port of the cleaning water or the outlet of the compressed air is appropriately provided at a position where it easily adheres depending on the shape, such as the lower opening vicinity 3a of the hopper 3, or the nozzle is provided so that the high-pressure cleaning water is appropriately emitted. It is desirable to provide it.

In the contaminated soil cleaning apparatus 1, the contaminated soil is cleaned as follows.
The soil contaminated with harmful substances is conveyed by the hydraulic shovel 2, and the contaminated soil is directly fed into the soil inlet of the hopper 3 provided at a height of about 5 m from the ground surface. As shown in FIG. 1, the hydraulic shovel 2 can put soil into the hopper 3 from the appropriately formed embankment. The soil inlet may be higher than the operator's line of sight of the hydraulic shovel 2, but the operator visually recognizes the soil inlet and the inside of the hopper 3 through the reflector 8 and cleans the soil with a drum. While checking the fall state to the machine 4 and the adhesion state to the hopper 3, the input amount and the input speed are adjusted. Further, by changing the direction and angle of the mirror surface of the reflecting mirror 8 as necessary, the operator can always visually recognize the inside of the hopper even when moving on the traveling hydraulic shovel 2. Therefore, it is possible to check whether or not the coagulated soil is accumulated in the hopper, and to add the soil while adjusting so that the soil surely falls into the drum type washing machine 4. In particular, soil containing a large amount of silt or viscosity is likely to adhere, so the contaminated soil is put into the hopper 3 while checking from time to time.

If there is agglomeration, adhesion, and agglomeration of soil in the hopper and the soil stays in the drum type washing machine 4 without dropping, the washing water is injected from the washing water supply port, that is, the nozzle 9, The soil is crushed and softened, and the drum type washing machine 4 efficiently drops the soil. At this time, the orientation of the nozzle 9 may be periodically rotated as shown in FIG. 3 to prevent soil adhesion or the like over a wide range in the hopper. In addition, when soil adheres to a part in the hopper and the soil is prevented from being thrown into the drum-type washing machine 4, the nozzle is arranged so that high-pressure washing water is jetted toward the part to which the soil is adhered. The direction of 9 may be operated.
Moreover, adhesion of the soil in a hopper is prevented effectively by operating similarly about compressed air.

  Thus, when the soil thrown into the hopper 3 is accommodated in the drum-type washing machine 4, washing water is further added and stirred to mix the contaminated soil and the washing water. And while a soil lump is crushed and slurried, a pollutant moves to the water phase from the particle | grain surface of contaminated soil.

  The soil washed by the drum type washing machine 4 is transferred to the wet vibrating sieve 5. Washing water is sprayed onto the sieve 5a as necessary from a water supply pipe (not shown) to wash out fine soil particles from coarse soil particles, and soil particles having a particle size of less than 2 mm and washing water. The mixture (slurry) falls through the mesh. Then, it slides down the inclined surface 5 b and is accommodated in the second tank 7. On the other hand, the coarse particles having a particle diameter of 2 mm or more remain on the mesh and are conveyed by the fact that the vibrating sieve 5a is disposed at an inclination. The coarse particles are dropped from the end of the vibrating sieve and are stored in the first tank 6 installed below the ground surface.

Next, an effect confirmation test using the device 1 according to the present invention will be described.
Lead-contaminated soil (contamination concentration: 1000 mg / kg) having a silt / clay content of 12% was introduced into the soil inlet of the hopper 3 provided at a height of about 5 m from the ground surface using a hydraulic shovel 2. At this time, the adhesion state of the soil inside the hopper 3 could be confirmed via the reflecting mirror 8 provided on the upper part of the hopper 3, and the amount of soil input and the input speed could be adjusted appropriately.
In addition, the soil sometimes adhered or stayed in the vicinity of the bottom wall 3a of the hopper 3 and the lower opening 3a. The soil adhered to the inside of the hopper 3 or the vicinity of the lower opening 3a by the injection of cleaning water and the blowing of compressed air. The coagulated soil can be crushed and the soil thrown into the hopper 3 can be efficiently dropped into the drum type washing machine 4.

Thereafter, the drum washer 4 was hydrated in the soil and the drum washer 4 was rotated at a speed of 6 rpm. After starting the introduction of the contaminated soil, the slurry discharged from the drum type washing machine 4 in about 10 minutes was dropped onto the wet vibrating sieve 5 having a 2 mm mesh and classified. The coarse particles on the sieve 5a and the slurry that passed through the sieve 5a could be smoothly accommodated in the first tank 6 and the second tank 7 installed below the ground surface.
Although the contaminated soil was washed continuously by the above method, it was confirmed that the soil transfer was not hindered and the contaminated soil could be washed stably.

Next, a conventional cleaning apparatus 10 that transports contaminated soil by gravity in a process from cleaning by a drum-type cleaning machine to classification by a wet vibration sieve and storage in a tank will be described below as a comparative example.
FIG. 6 is a schematic configuration diagram showing a conventional contaminated soil cleaning apparatus 10 used as a comparative example.
In this apparatus, since tanks 16 and 17 for collecting the soil after washing are installed on the ground surface, the drum type washing machine 14 is installed at a higher position than the washing apparatus shown in FIG. The hopper 13 to be charged is arranged at a height of approximately 12 m. Therefore, since it is difficult to directly input the contaminated soil to the hopper 13 arranged at a high place in the construction machine for earthwork such as the hydraulic shovel 12, the soil is transported to the hopper 13 using the pot conveyor 20 and input. did. Furthermore, in order to supply soil to the pot conveyor 20, it is necessary to install a lower hopper 21 on which the contaminated soil is directly input by a construction machine for earthwork.

The drum-type washing machine 14, the wet vibrating sieve 15, the first tank 16 and the second tank 17 provided in this apparatus are the same as those in the embodiment of the present invention shown in FIG. Although the first tank 16 and the second tank 17 are different on the ground surface, the relative positional relationship between the drum type washing machine 14 and the wet vibrating sieve 15 and the wet vibrating sieve 15 are different. The relative positional relationship between the first and second tanks 16 and 17 is set to be the same as that of the embodiment shown in FIG. Accordingly, the soil can be transferred by gravity in the process from the hopper 13 to the first tank 16 or the second tank 17 containing the soil.
The contaminated soil subjected to the washing treatment was lead-contaminated soil having an initial contamination concentration of 1000 mg / kg, and the silt / clay content was 5% to 10%.

  In this cleaning apparatus, contaminated soil is introduced into the lower hopper 21 using a self-propelled earthworking construction machine such as the hydraulic shovel 12. The soil is supplied from the lower hopper 21 to the pot conveyor 20 and conveyed to the upper hopper 13. The soil is put into the drum type washing machine 14 from the hopper 13 and the washing and sieving steps are performed in the same manner as when the washing apparatus 1 shown in FIG. 1 is used, and the first tank 16 and the second tank are respectively filled. Coarse grain and trickle are accommodated.

  When such a process was continued, the soil having a silt / clay content of about 5% to 8% was smoothly supplied to the drum type washer. However, in the soil having a silt / clay content of 10%, the soil gradually adhered to the pot conveyor 20, and the pot conveyor 20 became inoperable on the second day of operation due to the adhered soil. For this reason, it became necessary to temporarily stop the driving of the cleaning device, clean the driving device of the pot conveyor 20 and the like, and remove soil adhering to each place. Moreover, in the contaminated soil having 10% silt / clay, the soil is clogged at the discharge port of the lower hopper 21 used for placing the soil on the pot conveyor 20, and a recovery operation is required.

As can be seen from the above test, when the conventional contaminated soil washing apparatus 10 is used, if the contaminated soil contains about 10% or more of silt or clay, the soil adheres to the lower hopper 21 or the pot conveyor 20. There are many situations in which the cleaning process must be stopped, and it is likely that continuous operation becomes difficult.
On the other hand, in the cleaning apparatus 1 according to the present invention, there is almost no soil adhesion, and the cleaning process can be performed continuously, and stable operation is possible.

It is a schematic block diagram which shows the washing | cleaning apparatus of the contaminated soil which is one Embodiment of this invention. It is a schematic sectional drawing which shows the hopper used with the washing | cleaning apparatus shown in FIG. 1, and the nozzle which injects high-pressure washing water in this hopper. It is the schematic which shows operation | movement of the nozzle shown in FIG. It is a schematic sectional drawing which shows the other example of the nozzle which injects washing water in a hopper. It is the schematic which shows an example of arrangement | positioning of the discharge outlet which makes a washing water flow down to the wall surface in a hopper, and the water supply pipe which supplies cleaning water to these discharge outlets. It is a schematic block diagram which shows the washing | cleaning apparatus of the conventional contaminated soil.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,10: Cleaning apparatus of contaminated soil, 2,12: Hydraulic shovel, 3,13: Hopper, 4,14: Drum type washing machine, 5,15: Wet vibration sieve, 6,16: First tank, 7 , 17: Second tank, 8: Reflector, 9: Nozzle, 10: Water pipe,
20: Pot conveyor, 21: Lower hopper, 30: Hopper, 31: Opening serving as discharge port, 32: Water supply pipe

Claims (16)

A hopper into which soil contaminated with harmful substances is introduced;
A drum-type washing machine in which the soil is introduced from an opening provided in a lower portion of the hopper and is washed by adding water to the soil;
A vibrating sieve for classifying the soil discharged from the drum type washer;
A plurality of tanks for collecting the soil classified by the vibrating sieve,
The hopper is provided at a position where the soil can be input by a construction machine for earthwork that can rake and transport the ground surface traveling and soil,
The vibrating sieve is disposed at a position where the soil after washing discharged from the drum-type washing machine and transferred by gravity can be sieved,
The plurality of tanks are disposed at positions where the soil that has passed through the vibrating sieve and the soil that has remained on the vibrating sieve are transferred and accommodated by gravity, and at least one of the plurality of tanks is partially or entirely An apparatus for cleaning contaminated soil, characterized in that is installed at a position below the ground surface.   The contaminated soil cleaning apparatus according to claim 1, further comprising one or more reflecting mirrors that allow the operator of the construction machine for earthwork to visually recognize the hopper.   The contaminated soil cleaning apparatus according to claim 2, wherein the reflecting mirror is supported so that at least one of a mirror surface position, an up-down direction angle, and a horizontal direction angle can be changed.   A reflector operating device that adjusts at least one of the position, the vertical angle, and the horizontal angle of the reflector by an operator of the earthwork construction machine operating from a cockpit of the earthwork construction machine. The apparatus for cleaning contaminated soil according to claim 3.   A reflector that adjusts at least one of the position of the reflector, the vertical angle and the horizontal angle based on the position information of the operator of the construction machine for earthwork so that the operator can visually recognize the inside of the hopper. The cleaning apparatus for contaminated soil according to claim 3, further comprising an adjusting device.   The soil according to any one of claims 1 to 5, further comprising soil adhesion suppressing means for performing either one or both of supplying cleaning water and blowing compressed air in the hopper. Soil cleaning equipment.   7. The apparatus for cleaning contaminated soil according to claim 6, wherein the supply of the cleaning water causes the cleaning water to flow down on the inner surface of the hopper.   The apparatus for cleaning contaminated soil according to claim 6, wherein the supply of the cleaning water is to inject high-pressure cleaning water toward the inner surface of the hopper. The supply of the cleaning water is to discharge the cleaning water from a discharge port provided on the wall surface of the hopper and to flow down to the inner surface of the hopper,
The compressed air blowing is characterized in that the discharge of washing water from the discharge port is stopped, and the compressed air is blown out from the air discharge port provided in the vicinity of the discharge port. The contaminated soil cleaning apparatus according to claim 6.   The supply amount of the washing water, the injection angle or the injection speed of the high-pressure washing water to be injected can be adjusted according to the state of the soil charged into the hopper. The cleaning apparatus for contaminated soil according to any one of 8 to 8.   The vertical angle at which the compressed air is blown, the angle in the horizontal direction, the amount of air to be blown, or the pressure of the compressed air can be adjusted according to the state of the soil put into the hopper. The contaminated soil cleaning apparatus according to any one of claims 6 to 8. A hopper is provided at a position where the soil can be input by a construction machine for earthwork that can scrape and transport soil contaminated with traveling and harmful substances on the ground surface,
The operator of the construction machine for earthwork, while observing the state of the soil in the hopper through a reflector, put the soil directly into the hopper by the construction machine for earthwork,
While introducing soil from the hopper to the drum type washing machine by gravity, washing water is added to wash the soil,
The soil discharged from the drum washer is conveyed on a vibrating screen by gravity, and sieved by the vibrating screen,
Each of the soil sieved by the vibrating sieve is transported by gravity, and at least one of the plurality provided is accommodated in a tank installed in a position where a part or all of the soil is below the ground surface,
A method for cleaning contaminated soil, wherein the soil contained in each tank is taken out and transported to perform the next step.   In the hopper, either or both of supplying cleaning water and blowing compressed air are performed, and the soil is introduced by the construction machine for earthwork while suppressing adhesion of the soil into the hopper. 13. The method for cleaning contaminated soil according to claim 12.   When the soil is put into the hopper, the washing water is allowed to flow down to the wall surface in the hopper, and when the soil adheres to the hopper, the washing water is injected under high pressure or compressed air. 14. The method for cleaning contaminated soil according to claim 13, wherein spraying is performed.   The washing water flowing down the wall surface when soil adheres to the hopper, the discharge port provided on the wall surface of the hopper is covered, and the supply of the washing water flowing down to the wall surface in the hopper is obstructed After the supply of water is stopped, the soil on the discharge port is removed by blowing compressed air from the same discharge port, and a state in which a predetermined amount of washing water can flow down from the discharge port to the wall surface in the hopper is restored. The method for cleaning contaminated soil according to claim 14.   The step of throwing soil into the hopper by the construction machine for earthwork is an operation in which the operator of the construction machine for earthwork adjusts at least one of the position of the reflecting mirror, the vertical angle and the horizontal angle. The method for cleaning contaminated soil according to any one of claims 12 to 15, wherein the method is carried out by visually checking the inside of the hopper and confirming the state in the hopper.

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